Newly separated 9-month-old twins, born attached at the chest and abdomen, were introduced to the world Thursday at the Children's Hospital of Philadelphia.

Save for the oxygen tube still in little Amelia's nose, she and her sister, Allison, look like typical twins. They have their mother's blue eyes and were sporting matching pink hair bows at a news conference.

Despite their healthy appearance, it has been a long road to get them here, said mother Shellie Tucker.

"We found out about the girls on Nov. 14 of last year," Tucker said. "And we've been on this journey ever since. It's been a pure roller coaster of emotions."

Until they were separated last month, the girls shared their chest and abdominal walls, their pericardium -- the protective sack around the heart -- and their liver. Early on, a local doctor advised the Adams, N.Y., couple to terminate the pregnancy. They came to CHOP for a second opinion, where they were told the twins could be successfully separated.

"We didn't want them to go through a life of challenges," Tucker said. "Because it is challenging."

Tucker and husband, Greg, moved to Philadelphia in February to give birth here, and remain close to the girls while they were in the hospital. The twins were born March 1. Before they could undergo surgery, though, they had to gain weight and grow some extra skin.

"The limiting factor for when surgery can occur is really all about coverage," said the lead doctor on the case, pediatric surgeon Dr. Holly Hedrick.

"When they're separated, if they do not have any additional tissue on hand, they would have huge open, gaping wounds," Hedrick said.

So, back in June, the girls had expanders inserted under their skin. The balloonlike devices were inflated with silicone to grow -- and force new skin to grow around them.

"They're expanded once a week initially and then twice a week, and they become huge. It looks like the girls have two footballs on each side of them," Hedrick said.

When doctors decided they had enough extra skin to cover the separation wounds, it was time for surgery. It took a surgical team of nearly 40 people seven hours to complete the separation.

"We are very blessed and thankful to be here, and to have our two healthy little girls," Tucker said.

Tucker, 24, completed her college degree shortly before her first daughter, Allison, was sent home from the hospital Monday to join the couple and their 2-year-old son.

Amelia is still in the hospital recovering.

The Tuckers were the 21st set of conjoined twins to be separated at CHOP.